Typewriting machine



April 7, 1925. 1,532,192

J. C.. M LAUGHLIN TYPEWRITI NG MACHINE Filed May 13) 1921 Even/a": fi 7 Patented Apr. 7, 1925 UNITED stares" PATENT OF JOHN C. MOLAUGHLIN, OF EAST ORANGE,

FICE.

NEW JERSEY, AssIeNon 'ro nnnnnwoon TYPEWRITEB COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

(\ TYPEWBITING menmn Application filed May 18,

mechanism which arrests the type-bars when a near the platen to cause the types carried thereon to spring against the platen.

The invention is shown as applied to an Underwood Standard typewritmg machine in which type-bars carrying types at their ends strike against an anvil on the segment, just before the types reach the platen. The type-bars, being long and thin, are set in vibration by the blow, the momentum of the bars carrying them slightly forward into contact with the platen to print thereagainst. It is essential to time the engagement of a type-bar with the anvil or stop, so that it occurs a shade before the type reaches the platen, for, if the engagement occurs sooner, the type will not reach the platen at all and, if later, the type will strike the platen with the full momentum of the bar and cause several impressions of the type to be printed. In assembling the parts, it is necessary to secure exactness of relationship between type-bars, the abutment or stop and the platen, it being usually necessary for the type to be within less than five thousandths of an inch from the platen when arrested by the abutmentrand it being also necessary to leave a space of some thousandths of an inch between the type and the platen, so as to avoid blurring or double printing. The permissible variation in the too heavy an impression, compared with the position of the type when arrested by the abutment is therefore microscopic. If the type-bar strikes the abutment a trifle too soon, it"results that the type-bar springs excessively in reaching the platen, and the extreme tip of the type therefore makes 1921. Serial 110. 469,095,

justin the various type-bars delicately, so I that they will contact with the anvil at the exact desir .dpositions of the bars. For this purpose, the ordinary type-bars are prov ded wlth bendable eyes for contacting W1tl1 l}l1e anvil, and improved means are provided for adjusting the said adjustable portions of the type-bars.

Otherfeatures and advantages will hereinafter appear. In the accompanying drawings,

Figure 1 is a vertical section of a portion of an Underwood Standard typewriting machine, showing a type-bar as modified by the invention.

Figure 2 is a front elevation, partly sectioned, of the adjusting means. Figure 3 is a side elevation of the adjusting means applied to the adjustable portion of a type-bar.

Figure 4 is an end view of a portion of the adjusting means.

Figure 5 is an enlarged view of the adjust-able portion of a type-bar.

Figure dis a disassembled view of the upper portion of the adjusting means.

Type-bars 10 carrying types 11' are swung upwardly and rearwardly by depressing type-keys (not shown), the types striking against a platen 12. The type-bars are pivotally mounted at 13 in a segment 14 fixed to the frame of the machine, and are limited in their rearward movement by striking against a stop or anvil 15 fixed to the front wall of the segment. The typebars are adjusted to contact with the anvil slightly before the types 11 strike against the platen, the momentum and elasticity of the type-bars carrying the bars forwardly from the full-line position to the dotted line position of Figure 1 to print against the platen. It is essential that the bars contact with the anvil at the right time, for,

if they should strike too soon, the types would not print against the platen, and, if they should strike too late, the types would strike the platen with the full momentum of the type-bars and the vibration of the types against the platen would produce several impressions.

To insure that the type-bars strike against the anvil at the pro er time, provision is made of an adjustab e portion 20 on each type-bar, located adjacent the anvil when the bar is in raised position, as in Figure 1. It will be apparent that by varying' the position of portions 20, the position of the types relative to the platen at thetime the portions strike the anvil can be regulated at will. Each adjustable portion 20 is slotted to form a raised pro ection 21 and a slot 22. It is desirable to so adjust the distance which rojection 21 protrudes from the bar that t e projection will strike anvil 15 when the type 11 is a slight distance from the platen, as shown in full lines in Figure 1, the momentum of the bar setting up a vibration which carries the type forward to print against the platen. To vary the position of projection 21, there may be provided means in the form of an adjustingtool for spreading the slot in the direction of the projection, whereby the projection may be forced outwardly, said means being preferably incorporated in, and

r o erated in the manner of, a pair of pliers w ich may also be used to press the projection inwardly. The pliers comprise the usual two levers and 31 pivoted together at 32, the rearward ends of the levers forming handles 33 and 34, and the forward ends having pivotall mounted thereon jaws 35 and 36 at 37 an 38. Said jaws are mounted. for parallel movement towards and away from each other by having their rearward ends slotted at 39 and 40 for receiving pins 41 and 42 fixed to levers 30 and 31, respectively. When the handles 33 and 34 are pressed together, jaws 35 and 36 will move toward each other in the Well-known manner, maintaining their parallel relation throughout. The projection 21 is forced outwardly by a wedge-shaped member 50,

having a shank 51 fitting into an opening in one of the plier jaws, here shownas jaw 36, and held in place by a large-headed screw 52, countersunk in jaw 36 and threaded into the shank until a flange 53 at the end of the wedge abuts against the jaw 36. The wedge has a cross-section substantially similar to slot 22, but its dimensions adually increase towards the flange 53. he op 0- site jaw of the pliers. has an openin 54 or receiving the wedge when the ban les are pressed together. Assuming that projection 21 is to be forced outwardly, the wedge is inserted in slot 22 and the handles pressed together, the wedge entering opening 54 and jaw 35 forcing the type-bar downwardly on the wedge in the direction of flange 53 as .far as desired. The edge 55 of the wed e is slightly convex to force the center, or t e weakest and most easily adjusted portion of the projection, outwardly. If it is found that projection21 protrudes too far, the type-bar may be grasped across the portion comprising projection 21 and slot 22, between the parallel ends of jaws 35 and 36, and the projection pressed inwardl Variat1ons may be resorted to wlthin the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

The combination of a platen, a type-bar pivoted to swing against the platen, means for operating the type-bar, and means adjustable to arrest the type-bar near the completion of itsprinting stroke and at the exact required dxstance from the platen, said arresting means comprising a stationary sto and a co-operative stop formed for ad ustment on the type-bar, the latter stop in the form of a distortible eye integral with the body of the type-bar and projecting from said body and capable of being moderately opened or closed by bending the same. JOHN C. MCLAUGHLIN.

Witnesses:

EDITH B. LIBBEY, JENNIE P. THORNE. 

